1. Field of the Invention
The present invention relates to a probe for near-field light scattering, and to a process for producing the probe. More specifically, the present invention relates to a sharp-tipped probe which is used in near-field optical microscope and Raman spectrometer for detection of intensified scattered light, in which system the probe tip is brought into contact with an objective sample surface and simultaneously a light beam is projected onto the contact point. The present invention relates also to a process for producing the probe.
2. Description of the Related Art
In recent years, with progress in microfabrication of materials and in diversification of fabrication objects in various application fields, information analysis and measurement of microscopic spots are conducted for various materials and devices.
For inorganic materials, methods are developed for obtaining local information of the material with high reliability, the methods including use of an electron microscope. On the other hand, for soft materials such as those employed in molecular biology and organic devices, methods of non-destructive micro-analysis are not satisfactory. For example, an optical microscope is not capable of measurement in a size of the wavelength of a light beam or smaller. Infrared spectrometry and Raman spectrometry has also limitation in microanalysis from the same reason, and the signals obtained from a region of a size of wavelength order is weak and the signal intensity should be amplified.
For solving the above problems, in one method, a scattering type of probe is employed by utilizing positively the effect of electric field amplification by surface plasmon to exceed the limit of light diffraction. In another method, near-field light scattering is utilized with improved formation of a metal film on the probe (Japanese Patent Application Laid-Open No. 2005-164292). In a still another method, a Raman signal or a like signal from microscopic portion is optically detected by utilizing a surface amplification effect of a metal on a probe tip (Japanese Patent Application Laid-Open No. 2005-091353).
In still another method, for TERS (tip enhanced Raman spectroscopy) for obtaining local Raman spectral information, the probe tip is coated with silver by a silver mirror reaction.